Noether current from surface term, Virasoro algebra and black hole entropy in bigravity

Abstract

We consider the static, spherically symmetric black hole solutions in bigravity theory for minimal model with a condition $f_{μν} = C^{2} g_{μν}$ and evaluate the entropy for black holes. In this condition, we show that there exists the Schwarzschild solution for $C^{2} = 1$, which is unique consistent solution. We examine how the massive spin-2 field contributes and affects to the Bekenstein-Hawking entropy corresponding to Einstein gravity. In order to obtain the black hole entropy, we use a recently proposed approach which use Virasoro algebra and central charge corresponding to surface term in the gravitational action.

7 pages, version to appear in Physical Review D